An agricultural seeding machine such as a row crop planter or grain drill places seeds at a desired depth within a plurality of parallel seed trenches formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, chains and the like. Each row crop unit has a frame which is moveably coupled with a tool bar.
In areas where air seeder type equipment is used to seed small grains there has been a significant move to reduce input costs to the seeding process. One way to do this is to adopt no-till farming practices to reduce equipment and fuel costs. Another way is to combine the operations involved in seeding, for example tillage, seed bed preparation, fertilizer and seed placement. A further option is to utilize combined operations in a no-till farming practice.
There are machines presently available that have some ability to combine these operations. These are usually divided into two categories, air hoe drills and air disc drills. The first utilizes a combination of shanks with shovels or boots to create a trench for the seed, basically it ‘hoes’ a trench. Examples of such tools are John Deere 1820, Bourgault 5710, Morris Maxim II, 8900 and 9000, or Case ATX Series. The second type utilizes disc type openers to create the seed trench. Examples of such tools are John Deere 1890, Bourgault 5720, Morris Never Pin or Case SDX Series.
Not all of these machines are capable of placing fertilizer at the same time as seeding. Generally it is easiest to place dry granular fertilizer at the same time as seeding since that type of fertilizer can be distributed by a similar air delivery system. The application of liquid fertilizer requires an additional delivery and distribution system, typically not supplied by the air seeder manufacturer. The application of gaseous fertilizer such as anhydrous ammonia (also referred to as NH3) also requires an additional delivery and distribution system, typically not supplied by the air seeder manufacturer. A further difficulty with NH3 is the requirement to effectively seal the gas into the ground. This is typically the most challenging task for these openers.
To effectively retain the gas in the ground it is necessary to place the gas accurately in a trench and seal it therein. To achieve this it is preferable to create a small, neat trench at constant depth and close the trench quickly and efficiently afterwards. The difficulties encountered with known designs are in all aspects of this operation. Those devices suffer from one or more of the following detrimental actions: 1) too much soil disturbance creating a large trench with soil displaced significantly; 2) lack of depth control; and 3) inability to close or seal the trench immediately after release of the gas.
It is known to use a fertilizer opener with a boot/scraper that is entirely within the profile of the opener disc and has no interference with the opposite trench sidewall to create a narrow trench. This configuration has experienced difficulties operating in adverse conditions since the boot/scraper is not pressed against the opener disc sufficiently to prevent soil, mud and/or residue from entering therebetween and causing the opener disc to quit turning and push the boot far out thus creating an excessive trench. Other known fertilizer openers use boots and scrapers that protrude significantly from the trench cut by the opener disc, but displace too much soil from the trench and make it difficult to close and seal the trench.
Other types of fertilizer openers allow use of the three main fertilizer types (dry granular, liquid and gaseous anhydrous ammonia). However, such openers require different types of attachments and mounting hardware changes to swap from one fertilizer type to another. This is labor intensive, with increased costs and chances of assembly error.
What is needed in the art is a fertilizer opener which quickly and easily allows for use with dry, liquid and/or gaseous fertilizers.